1. Field of the Invention
The invention relates to electrical systems and devices. More particularly, the invention relates to a matrix board with a panel having a planar surface for supporting a first circuit and a parallel surface for supporting a second circuit and pins for making connections between circuits. Most particularly the invention relates to an assembly of matrix board modules and I/O board modules adapted for connection of a hydrophone cable and an accelerometer cable.
2. Discussion of the Related Art
In an acoustic test facility, analog sensor signals are routed to data acquisition channels for analysis. Although data acquisition is conceptually simple, test facilities may have a large number of sensors and a large number of acquisition channels to connect. Connecting specific sensors to specific acquisition channels and checking all newly made circuits takes considerable effort. A change in test series requires reconfiguring the sensors and data acquisition channels and introduces the potential for error due to misrouting.
A cable patch panel is the primary apparatus used for reconfigurable test systems. A cable patch panel provides for routing all sensor cable to an input junction box panel and all data acquisition cables to an output junction box panel. Jumper cables make the connection to patch signals between the input junction box panel and the output junction box panel. This allows any sensor to be routed to any data acquisition channel by way of the jumper cables. While this apparatus is adequate when there are only a few sensors and channels, when the number of sensors and channels becomes large, the system becomes cumbersome. For example, in order to reroute a single connection, it may be necessary to disconnect a number of jumpers to access a desired cable. This introduces the potential for introducing errors when reattaching jumper cables. In addition, the size and weight of a large patch panel can make a system impractical for tests involving large numbers of sensors and channels.
Mechanical relay matrix boards are also used for signal routing. Relay boards connect an input to an output through a relay. However relays have limitations. Commercially available relay matrix boards have a limited number of channels. Typically, relays used for this purpose provide for 24 inputs and 24 outputs. Multiple relays can be used, but this increases cost and degrades signal quality.
Integrated circuits with solid state relays are also used for switching signals. Solid state relays are more compact than mechanical relays. However, solid state relays are active electronic devices that introduce small loads in signal lines. The sum of small loads becomes significant in large channel systems resulting in amounts of signal distortion and loss. Amplifiers have been added to solid state matrix boards to make up these losses. However, this introduces signal directionality problems. In addition, most solid state relays are able to pass only low differential signals. They cannot be used for ICP(IEPE-type) device signals, i.e. signals from Integrated Circuit Piezoelectric (Integrated Electronics Piezo Electric) devices. ICP(IEPE-type) devices have transducers to measure parameters such as dynamic pressure, force strain and acceleration. ICP(IEPE-type) devices include hydrophones and accelerometers.
There is a need in the art for improvements in junction boards to accommodate hydrophone and accelerometers cables.